ZPEnergy.com - The new 'look' of superconductivity

Equilibrium patterns in superconducting lead: left, Prozorov’s “soap-foam” pattern; and right, the Landau laminar pattern. Both images are obtained at the same temperature and magnetic field. The only difference is how the magnetic field was increased or decreased to reach equilibrium. Credit: Ames Lab

Like the surface motif of a bubble bath, the spatial distribution of a magnetic field penetrating a superconductor can exhibit an intricate, foam-like structure. Ruslan Prozorov at the U.S. Department of Energy’s Ames Laboratory has observed these mystifying, two-dimensional equilibrium patterns in lead samples when the material is in its superconducting state, below 7.2 Kelvin, or minus 446.71 degrees Fahrenheit.

Through innovative research to relate the complex geometry of the equilibrium patterns to the macroscopic physical properties, such as magnetism, Prozorov has shown that the shape of the entire sample determines the pattern topology and overall magnetic behavior of the system – a significant finding that represents a major contribution to the field of superconductivity. “You can have the same volume and same mass, but if you just change the shape, you get a different type of response from the sample and a different type of geometry of the equilibrium field pattern,” he said. “The discovery has reopened the whole field of equilibrium in type-I superconductors, which had gone dormant because it was considered closed.”
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Read the whole story here: http://www.physorg.com/news102912757.html
Source: Ames Laboratory